Stunned onlookers in the Carnhill area in Londonderry told how youths attacked police with bottles and stones and how young girls jumped on top of PSNI Land Rovers as the party spiralled out of control.

The violence occurred as the Government unveiled new proposals to tackle underage drinking.

Ministers have stated that parents who allow children to drink in public could be prosecuted, and it could become illegal for under-18s to be regularly found with alcohol.

The trouble in Derry flared when word was spread by youths on their mobile phones and a crowd of up to 200 young people — many of whom had been drinking — came into the estate and congregated near the house where a 17th birthday party was taking place on Friday night.

A fight broke out among some of the teenagers in front of horrified residents, who contacted the police.

But when officers arrived, many in the crowd launched an attack on them with bottles, stones and other missiles.

A police spokesman said a 15-year-old male was subsequently charged with riotous behaviour and is expected to appear at a youth court sitting at Londonderry Magistrate's Court on June 18.

SDLP councillor Mary Bradley, who lives in the Carnhill area said residents had contacted her to say they were left frightened and angry: "A few people on the estate had the windscreens of their cars put in with bricks during the riot. This is a quiet area and people don't expect something like this.

"What happened was a disgrace and my information is that the residents in this area are keen to organise themselves so that if this ever happens again people will be prepared to deal with it."

She also revealed locals were "alarmed" at the age of some of those involved in the violence: "The girls were every bit as bad as the boys. Some of them were even jumping up and down on the the police Land Rovers.

"Parents need to keep a closer eye on what teenagers are getting up to."